properly handle missing pandas module
properly handle missing pandas module

sdss/marvin,sdss/marvin,sdss/marvin,bretthandrews/marvin,bretthandrews/marvin,albireox/marvin,albireox/marvin,albireox/marvin,bretthandrews/marvin,albireox/marvin,sdss/marvin,bretthandrews/marvin